Global trajectory correction algorithms in CLIC and main Linac alignment tolerances

Alignment tolerances in linear colliders are closely dependent on the expertise in beam trajectory handling, particularly in CLIC where wake fields dominate. Control of the on-momentum trajectory only can be considered as in a straightforward one-to-one scheme. However, more sophisticated processes can be contemplated, involving several correctors and beam position monitors. Moreover, it is possible to apply gradient variations from the nominal values in order to simulate and better compensate dynamical effects, as first suggested at SLAC. The present paper describes various methods applied with assumptions reflecting the most recent characteristics of the CLIC main Linac and beam. Calculations for several sets of parameters are presented. Alignment requirements are alleviated and fall in the feasibility domain while maintaining the previously mentioned key parameters within specifications